Metal manufacture



. Patented Nov. 4, 1924.

um'rso STATES PATENT OFFICE.

WILLIAM R. HURD, 2ND, OF BEVERLY, MASSACHUSETTS, ASSIGNOR TO UNITED SHOEMACHINERY CORPORATION, OF PATERSON, NEW JERSEY, A CORPORATION OF NEWJERSEY.

METAL MANUFACTURE.

Application filed March 11, 1918. Serial No. 221,812.

To all whom it may concern:

Be it Known that I, WILLIAM R. HURD, 2nd, a citizen of the UnitedStates, residing at Beverly, in the county of Essex and State ofMassachusetts, have invented certain Improvements in Metal Manufacture,of which the following description, in connection with the accompanyingdrawings, is a specification, like reference characters on the drawingsindicating like parts in the several figures.

This invention relates to the treatment of corrodible metal surfaces inthe manufacture of machine parts, metal tools and the like. For'the sakeof illustration, the invention is herein set forth with particularreference to its applicability to the manufacture of cutters used fortrimming the sole edges of shoes. It is to be understood, however, thatthe invention is not at all limited to the treatment of edge-trimmingcutters, but is applicable generally to the manufacture and reclamationof tools, machine castings and parts and various other metallic articleshaving iron and steel or other corrodible metal surfaces.

A great deal of difliculty is experienced in the preservation of suchmetal surfaces from corrosion which lessens their efficiency and injurestheir appearance. With this in vlew, it is one object of my invention toprovide an improved method of surfacing metal articles, the practice ofwhich will 1nsure the preservation of the articles only while they arein use but when they are. in storage or otherwise idle.

In addition to the general liability of corrosion by exposure ofmachines, parts and tools 'to dampness and other corroding influencesliable to produce rust, when they are in storage or in stock, manymachines and tools, when in use, are operated only intermittently withintervening periods 0 idleness. This is sometimes due to the fact thatmachines or devices as a whole are operated only occasionally. In manyinstances, of which edge-trimming cutters furnish a good example, theparticular liability to corrosion is due to the fact that the necessaryequipment of a-machine includes a considerable number of spare parts orinterchangeable tools. For instance, edgetrimming cutters are eachprofiled to treat sole-edges of only one style, so that the cuttreatednot ters have to be interengaged as shoes of different styles come tothe machines. The result is that although any given cutter has usually along knife, it is subject to frequent and considerable periods ofidleness. Such tools consequently are especially liable to become rustyand thus to cause damage to the work operated upon.

On the other hand, it is for many uses disadvantageous to have metalsurfaces too bright or highly polished. Here again the use ofedge-trimming cutters may be referred to as illustrative of this partofthe problem. In performing an edge-trimming operatlon, the operatorholds the shoe in his hands without any support, or guide whatever,anddraws its sole edge past the rapidly rotating cutter. There is nothingto control the depth of cut except the operators judgment and skill. Thereflection of light from a bright cutter has a tendency to dazzle theoperator, making him unable to cause the trimming to extend to just theright depth. In short, either extreme in the condition of the cutterwill result in unsatisfactory work.

A further difficulty met with in cutters heretofore obtainable has beenthat, as is very generally true of tools and machine parts, they arecovered with a thick heavy oil by their manufacturer to protect themfrom rust while in stock. t is not feasible to clean this substance allon from between the teeth before a cutter is 'fi st used, and so itgreases the grinding wheel badly when the cutter is reground the firsttime. The wheel then has to be dressed off to clean it. Moreover, theslushing of tools and machine parts by coating them with heavy oil ismany times objectionable because of the liability of soiling the handsor clothing of the, operator or the work operated upon, this f tendencybeing aggravated by the obvious fact that such oil-coated surfaces catcha great deal of dust and dirt.

In view of these difficulties and in ac- .cordance with a furtherobject, my invention is directed to the protection of a metal surfacewith a preservative coating which is not disagreeable to the touch, isnot destroyed by handling or ordinary use, and will not soil the handsor clothing.

In the attainment of the above-stated and other objects, it isaparticularly advantageous characteristic of 'the invention that itprovides metal surfaces liable to corrosion with a substantiallyindestructible dull finish, which will not require cleaning, with conse-5 quent danger of brightening. In'the illustrated exemplification of theinvention, the articles to be treated are immersed in a bath comprisinghot parafiin and then, immediately upon removal from the bath, the

coated articles are subjected to an air blast moved in order that theair blast may actto remove the surplus coating. When different sides ofthe articles are to be coated and the nature of the articles permits,the air jet and the coated articles are relatively against diiferentsides of the articles. In the treatment of many metallic articles, it ispreferable to turn or whirl the articles in "the air blast, thusgenerating centrifugal force which aids in removing the surplus coatingsubstance. This may be. effected where the articles are of such acharacter as to lend themselves to it by utilizing the air jet itself towhirl the articles. The surfaces of the articles hold a very thin layerof coating substance effectually against removal by any ordinaryhandling to which the articles are subjected, and the dull char-' acterof the coating diffuses any light reflected thereby. The articles arethus preserved indefinitely in a dull, greaseless and rustlesscondition.

These and other aspects of the invention will be better understood fromthe follow- 5 ing description of a preferred practice coating the enedand ground, it is preferably surface roughened. This operation nay beperformed in any way that will produce minute sharp edged abrasions inthe surface or surfaces to be treated. The general dimensions 5 of theseabrasions and of their distances from each other may well be of the same.order of magnitude as the wave length of light in order to form a dull,non-refiectin surface. I perform the roughening pre erably by a sandblast, as shown in Fig. 2.

The apparatus there shown comprises a rotating table 18 having a, numberof spindles 20 on which the cutters are loosely mounted. The sand box 22rotates above the table 18 and has a plurality of nozzles 24 throughwhich" the sand isdrivenl The cutters are turned in both directions bythe-impact as they pass through a sand stream so that all parts of theirsurface are treated. Any sand blasting apparatus may be used, and

the same forms no part of the present invention and need not be furtherdescribed. This operation removes the scale and soda and creates a matfinish ori the metal.

The cutter is then coated with an airproof and moisture proof, substancewhich is solid under ordinary conditions and pins on a plate 25 (Fig. 3)arranged to rotate and to pass beneath the surface of the meltedparafiin or other substance 26. The

bath may be heated by flame jets 28.

In the illustrated exemplification of the method, the heat-retainingarticles to be treated are heated by immersion in the hot melted coatingsubstance to a temperature which will maintain the coating in a liquidstate for a substantial period after the re- I moval of the articlesfrom the coating bath.

After the cutters 'or other articles to be treated have been coated,they are removed from the bath and before the coating solidifies theyare transferred from the bath to another locality where they aresubjected to an air blast indicated at 30. The illustrated apparatus isso designed that the impact of the air will rotate or whirl the cuttersor any other, articles, provided they are rotatively mounted and have ashape that renders them responsive to the propelling force of the air.When so treated, the rotative action of the articles generatessufiicient centrifugal force to aid materially in removing the surpluscoating substance. Moreover, the surplus coating substance is removedfrom all the treated surfaces, including a recess such as that"illustrated at 10. I have found that this removes a large quantity ofthe coating substance which then runs back into the bath, but that theminute abrasions caused by the roughening operation retain enough of thematerial to make'a rust-proof coating which it is very hard to remove.It appears to be actually incorporated in the finely abraded surface,being probably held by minute sharp fins struck up by the sand blast,does not rub ofl", and 1 have found that it remains unaltered after longuse, and that surfaces so treated become neither polished nor rusty. Theamount of the coating material remaining on the faces 32 of the teeth isso slight that it does not interfere with the operatlon of the grindingwheel. Moreover, metallic articles so treated are not open to thedisetters advantages, including those heretofore pointed out, arisingfrom the slushing of the articles with heavy oil.

My invention thus provides for the manufacture of a metal surface havinga permanent non-corrodible indestructible dull finish.

' Having described my invention, what ll claim as new and desire tosecure by Letters Patent of the United States is 1. That improvement inthe art of treating metallic articles which consists in simultaneouslyheating and coating a metallic article by immersing it in a bath of hotmelted' coating substance that solidifies at ordinary atmospherictemperatures, removing said article from said coating bath, anddirecting an air jet against the article to re move surplus coatingsubstance before it solidifies.

2. That improvement in the art of treating metallic-articles whichconsists in applying a coating of liquefied substance that solidifiesunder ordinary conditions, and removing surplus coating substance fromthe article by blowing against the article in such a way as to rotatethe latter before the coating solidifies, thus generating centrifugalaction.

3. The improved method of treating an article which consists in applyinga coating of liquefied substance that solidlfies under ordinaryconditions, and simultaneously rotating the article about an axisintersecting it and blowing against the coating substance on thearticle. I

4. That improvement in the art of treating metallic articles whichconsists in a plying a coating of a liquefied waxy su stance to anarticle, and removing the surplus coating substance by the conjointefiect of centrifugal force and a blast of air.

1 '5. That improvement in the art of treating metallic articles whichconsists in coating an article with a liquefied waxy substance,

, and removing the surplus coating substance from the article by causingan air-blast to impinge on and rotate the article.

6. That improvement in the art of treating metallic articles whichconsists in immersing an article in a bath of liquefied Waxy substance,removing the article from said bath, and blowing against the coatingsubstance while rotating the article so as to generate centrifugal forceto remove the surplus coating substance before it solidifies.

7. That improvement in the art of treating metallic articles whichconsists in immersing an article in a bath comprising liquid parafiin,raising the article out of said bath, and removing surplus'parafin. fromthe article by blowing against the liquid coating of parafin and turningthe article so as to blow against all parts of its surface.

8. That improvement in methods of treating metallic articles whichconsists in giving an article an excessive coating of a liq- -uid waxysubstance, and thereafter blowing against the liquid coating whilerelatively moving the article and the blowing means so as to removesurplus coating substance from difierent sides of the article.

9. That improvement in methods \of treating metallic articles whichconsists in givin an article an excessive coating of a liqui substancethat will solidify at ordinary atmospheric temperatures, and thereaftersimultaneously blowing against the coating and whirling the article soas to remove surplus coating substance.

10. That improvement in methods of treating metallic articles whichconsists in giving an article an excessive coating of a liquid substancethat will solidify under ordinary conditions, and thereafter removingsurplus coating substance from the article by the conjoint efi'ect of anair-blast and centrifugal force. I

11. That improvement in the'art of treating metallic articles, whichconsists in giving an article having a recess an excessive coating of aliquid waxy substance that will solidify under ordinary conditions, andthereafter removing surplus coating substance from the recess bywhirling the article and simultaneously causing a jet of air to impingeon the coating in saidrecess.

in testimony whereof I have signed my name to this specification.

LIAM R. HURD, 2ND.

